libmymath.a:my_add.o my_sub.o
	ar -rc $@ $^
my_add.o:my_add.c
	gcc -c my_add.c
my_sub.o:my_sub.c
	gcc -c my_sub.c
.PHONY:output
output:#发布软件的过程
	mkdir -p mylib/include
	mkdir -p mylib/lib
	cp -f *.a mylib/lib
	cp -f *.h mylib/include
.PHONY:clean
clean:
	rm -f *.o libmymath.a
